/*
 * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
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 *
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 *
 *
 *
 *
 */

package javax.management;


import com.sun.jmx.mbeanserver.GetPropertyAction;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;

import java.security.AccessController;

/**
 * This class represents numbers that are arguments to relational constraints.
 * A NumericValueExp may be used anywhere a ValueExp is required.
 *
 * <p>The <b>serialVersionUID</b> of this class is <code>-4679739485102359104L</code>.
 *
 * @serial include
 * @since 1.5
 */
@SuppressWarnings("serial")
    // serialVersionUID not constant
class NumericValueExp extends QueryEval implements ValueExp {

  // Serialization compatibility stuff:
  // Two serial forms are supported in this class. The selected form depends
  // on system property "jmx.serial.form":
  //  - "1.0" for JMX 1.0
  //  - any other value for JMX 1.1 and higher
  //
  // Serial version for old serial form
  private static final long oldSerialVersionUID = -6227876276058904000L;
  //
  // Serial version for new serial form
  private static final long newSerialVersionUID = -4679739485102359104L;
  //
  // Serializable fields in old serial form
  private static final ObjectStreamField[] oldSerialPersistentFields =
      {
          new ObjectStreamField("longVal", Long.TYPE),
          new ObjectStreamField("doubleVal", Double.TYPE),
          new ObjectStreamField("valIsLong", Boolean.TYPE)
      };
  //
  // Serializable fields in new serial form
  private static final ObjectStreamField[] newSerialPersistentFields =
      {
          new ObjectStreamField("val", Number.class)
      };
  //
  // Actual serial version and serial form
  private static final long serialVersionUID;

  /**
   * @serialField val Number The numeric value
   *
   * <p>The <b>serialVersionUID</b> of this class is <code>-4679739485102359104L</code>.
   */
  private static final ObjectStreamField[] serialPersistentFields;
  private Number val = 0.0;

  private static boolean compat = false;

  static {
    try {
      GetPropertyAction act = new GetPropertyAction("jmx.serial.form");
      String form = AccessController.doPrivileged(act);
      compat = (form != null && form.equals("1.0"));
    } catch (Exception e) {
      // OK: exception means no compat with 1.0, too bad
    }
    if (compat) {
      serialPersistentFields = oldSerialPersistentFields;
      serialVersionUID = oldSerialVersionUID;
    } else {
      serialPersistentFields = newSerialPersistentFields;
      serialVersionUID = newSerialVersionUID;
    }
  }
  //
  // END Serialization compatibility stuff


  /**
   * Basic constructor.
   */
  public NumericValueExp() {
  }

  /**
   * Creates a new NumericValue representing the numeric literal @{code val}.
   */
  NumericValueExp(Number val) {
    this.val = val;
  }

  /**
   * Returns a double numeric value
   */
  public double doubleValue() {
    if (val instanceof Long || val instanceof Integer) {
      return (double) (val.longValue());
    }
    return val.doubleValue();
  }

  /**
   * Returns a long numeric value
   */
  public long longValue() {
    if (val instanceof Long || val instanceof Integer) {
      return val.longValue();
    }
    return (long) (val.doubleValue());
  }

  /**
   * Returns true is if the numeric value is a long, false otherwise.
   */
  public boolean isLong() {
    return (val instanceof Long || val instanceof Integer);
  }

  /**
   * Returns the string representing the object
   */
  public String toString() {
    if (val == null) {
      return "null";
    }
    if (val instanceof Long || val instanceof Integer) {
      return Long.toString(val.longValue());
    }
    double d = val.doubleValue();
    if (Double.isInfinite(d)) {
      return (d > 0) ? "(1.0 / 0.0)" : "(-1.0 / 0.0)";
    }
    if (Double.isNaN(d)) {
      return "(0.0 / 0.0)";
    }
    return Double.toString(d);
  }

  /**
   * Applies the ValueExp on a MBean.
   *
   * @param name The name of the MBean on which the ValueExp will be applied.
   * @return The <CODE>ValueExp</CODE>.
   */
  public ValueExp apply(ObjectName name)
      throws BadStringOperationException, BadBinaryOpValueExpException,
      BadAttributeValueExpException, InvalidApplicationException {
    return this;
  }

  /**
   * Deserializes a {@link NumericValueExp} from an {@link ObjectInputStream}.
   */
  private void readObject(ObjectInputStream in)
      throws IOException, ClassNotFoundException {
    if (compat) {
      // Read an object serialized in the old serial form
      //
      double doubleVal;
      long longVal;
      boolean isLong;
      ObjectInputStream.GetField fields = in.readFields();
      doubleVal = fields.get("doubleVal", (double) 0);
      if (fields.defaulted("doubleVal")) {
        throw new NullPointerException("doubleVal");
      }
      longVal = fields.get("longVal", (long) 0);
      if (fields.defaulted("longVal")) {
        throw new NullPointerException("longVal");
      }
      isLong = fields.get("valIsLong", false);
      if (fields.defaulted("valIsLong")) {
        throw new NullPointerException("valIsLong");
      }
      if (isLong) {
        this.val = longVal;
      } else {
        this.val = doubleVal;
      }
    } else {
      // Read an object serialized in the new serial form
      //
      in.defaultReadObject();
    }
  }


  /**
   * Serializes a {@link NumericValueExp} to an {@link ObjectOutputStream}.
   */
  private void writeObject(ObjectOutputStream out)
      throws IOException {
    if (compat) {
      // Serializes this instance in the old serial form
      //
      ObjectOutputStream.PutField fields = out.putFields();
      fields.put("doubleVal", doubleValue());
      fields.put("longVal", longValue());
      fields.put("valIsLong", isLong());
      out.writeFields();
    } else {
      // Serializes this instance in the new serial form
      //
      out.defaultWriteObject();
    }
  }

  @Deprecated
  public void setMBeanServer(MBeanServer s) {
    super.setMBeanServer(s);
  }

}
